Re: [Bug fix PATCH v4] Reusing a resource structure allocated bybootmem

From: Yasuaki Ishimatsu
Date: Thu Apr 18 2013 - 19:49:31 EST


2013/04/19 8:28, Toshi Kani wrote:
On Fri, 2013-04-19 at 08:33 +0900, Yasuaki Ishimatsu wrote:
:

+static struct resource *get_resource(gfp_t flags)
+{
+ struct resource *res = NULL;
+
+ spin_lock(&bootmem_resource_lock);
+ if (bootmem_resource.sibling) {
+ res = bootmem_resource.sibling;
+ bootmem_resource.sibling = res->sibling;
+ memset(res, 0, sizeof(struct resource));
+ }
+ spin_unlock(&bootmem_resource_lock);


I prefer to keep memset() outside of the spin lock.

spin_lock(&bootmem_resource_lock);
if (..) {
:
spin_unlock(&bootmem_resource_lock);
memset(res, 0, sizeof(struct resource));
} else {
spin_unlock(&bootmem_resource_lock);
res = kzalloc(sizeof(struct resource), flags);
}

Hmm. It is a little ugly. How about it?

spin_lock(&bootmem_resource_lock);
if (bootmem_resource.sibling) {
res = bootmem_resource.sibling;
bootmem_resource.sibling = res->sibling;
}
spin_unlock(&bootmem_resource_lock);

if (res)
memset(res, 0, sizeof(struct resource));
else
res = kzalloc(sizeof(struct resource), flags);


Sounds good to me.

Great. I'll update it.

Thanks,
Yasuaki Ishimatsu


Thanks,
-Toshi




--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/